Thromb Haemost 1989; 61(02): 262-265
DOI: 10.1055/s-0038-1646572
Original Article
Schattauer GmbH Stuttgart

Influence of Whole Blood on Standard Curve for Heparin Measurement - Possible Heparin Binding by Red Cells

E Melissari
The Thrombosis Research Unit, King’s College School of Medicine and Dentistry London, UK
,
C Thye
The Thrombosis Research Unit, King’s College School of Medicine and Dentistry London, UK
,
M F Scully
The Thrombosis Research Unit, King’s College School of Medicine and Dentistry London, UK
,
V V Kakkar
The Thrombosis Research Unit, King’s College School of Medicine and Dentistry London, UK
› Author Affiliations
Further Information

Publication History

Received 18 July 1988

Accepted after revision 25 November 1988

Publication Date:
30 June 2018 (online)

Summary

Measurement of heparin ex vivo is usually with reference to standard curve prepared with a “spiked” normal human plasma pool (NHP). When the calibration curve was prepared by addition of heparin to whole blood before plasma separation, although the linear relationship was maintained the slope was increased in comparison to the classical standard calibration curve. It is concluded that the preparation of the calibration curve by addition of heparin to NHP may give erroneously high heparin levels in treated patients’ plasma, leading perhaps to inappropriate dosage. It was also observed that when heparin was added to blood of different haematocrit (prepared by addition of washed RBC to plasma) and plasma prepared, the subsequent APTT was decreased with the fall in haematocrit; suggesting that the laboratory monitoring of heparin treatment should take into account the patient’s haematocrit.

 
  • References

  • 1 Teien AN, Lie M. Heparin assay in plasma: A comparison of five clotting methods. Thromb Res 1975; 7: 777-778
  • 2 Yin ET. A new single stage measurement of heparin by antifactor Xa. Sem Thromb Haemostas 1985; 11: 243-244
  • 3 Handeland GF, Abilgaard U. Assay of unfractionated and LMW heparin with chromogenic substrates: Twin methods with factor Xa and thrombin. Thromb Res 1984; 35: 627-636
  • 4 Teien AN, Lie M. Evaluation of an amidolytic heparin assay method. Increased sensitivity by adding purified antithrombin III Thromb Res 1977; 10: 399-410
  • 5 Bratt G, Tömebohm E, Lockner D, Bergström K. A human pharmacological study comparing conventional heparin and a low molecular weight heparin fragment. Thromb Haemostas 1985; 53: 208-211
  • 6 Ockleford R. Heparin 1986. Indications and effective use Drugs 1986; 31: 81-92
  • 7 Talstad I. Heparin therapy adjusted for body weight. Am J Clin Pathol 1985; 83: 378-381
  • 8 Fernandez F, van Ryn J, Ofusu FA, Hirsh J, Buchanan MR. The haemorrhagic and antithrombotic effects of dermatan sulphate. Br J Haematol 1986; 64: 309-317
  • 9 Ofusu FA, Blajchman MA, Modi GG, Smith LM, Buchanan MR. The importance of thrombin inhibition for the expression of the anticoagulant activities of heparin dermatan sulphate, low molecular weight heparin and pentosan polysulphate. Br J Haematol 1985; 60: 695-704
  • 10 Handin RI, Cohen HJ. Purification and binding properties of human platelet factor four. J Biol Chem 1976; 251: 4273-4282
  • 11 Contant G, Gouault-Heilmann M, Martinoli JL. Heparin inactivation during blood storage. Its prevention by blood collection in citric and theophylline adenosine, dipyridamole - C.T.A.D. mixture Thromb Res 1983; 31: 365-374
  • 12 Bleiberg I, MacGregor I, Aronson M. Heparin receptors on mouse macrophages. Thromb Res 1983; 29: 53-61